The present invention relates to a method and system for continuous cleaning of the underwater bottom, making it possible to hoist up to the surface heavy viscous products deposited or scattered at the water bottom, as result of a leakage from oil-fuel tanks of stranded or sunken ships creating pollution.
Such products may, for example, be hydrocarbons or heavy oil residues having a specific gravity higher than that of the surrounding water, and which can not be effectively collected mechanically, for example, by dredging. Dredging of these products might be contemplated but would suffer from the following major drawbacks:
conveyance of very large quantities of inert material (sand and water) from the water bottom, resulting in difficult separation and discharge problems, PA0 unavoidable tar scattering (i.e., enlargement polluted zone), PA0 requirement of a pumping system having a pumping rate of about 500 m.sup.3 /hours, which is abrasion resistant, capable of being steadily displaced on the water bottom, and not very sensitive to water currents.